This invention relates to an industrial robot having contact sensing to avoid accidents and collisions of a robot arm with an operator, another robot, or any other object and avoid injury or damage to operators, other equipment, or the robotic arm itself.
Various approaches to solving this problem have been tried in the prior art. U.S. Pat. No. 4,514,616 discloses a robot arm collision detection mechanism having two movable members which are engaged in a cam surface-cam follower arrangement. A collision causes one member to become displaced from its "home position" and this displacement triggers a control switch.
U.S. Pat. No. 4,540,869 discloses a shaft inside a collision detection mechanism. When the welding torch nozzle moves sideways and strikes an object tip, the shaft is displaced. This lateral displacement of the shaft from its usual position triggers a control switch.
These solutions are mechanically complex and add measurably to the weight of the robot arm.